There's already a previous port of Numpty Physics to the N950, but this one uses the latest source code and tries to integrate a bit better (Swipe lock, etc..) with Harmattan, especially since the side menus are hard to hit with Swipe enabled:

Some fixes for the crashes are in the Git repo already, I'll try to upload the sources to OBS soon, so a new binary package with the fixes gets built. In the mean time, you can build it yourself in Scratchbox (Platform SDK).